mannesman



model.) MANNESM-ANNI 2 Sheets----Sheet '1'.

L MANUFACTURE OF SEAMLESSI'TUBES.

No. 361,958. Patented Apr. 26,1887.

(ModeL) 2 ShQetS- -Sheet 2.

. R. MANNESMANN.

MANUFACTURE OF SEAMLESS TUBES. No. 361,958. Patented Apr. 26, 1887.

UNITED STATES PATENT ()EEIoE.

REINHARD MANNESMANN, OF REMSCHEID, GERMANY.

MANUFACTURE OF SEAMLESS TUBES.

SPECIFICATION forming part of Letters Patent; No. 361,958, dated April26, 1887. Application filed March 28,1887. Serial No.232fl93. (ModcLlPatented in Belgium August 14,1886, No. 54,857.

To all whom it may concern.-

Be it known that I, REINHARD MANNES- MANN, of Remscheid, Germany, haveinvented certain Improvements in Apparatus for Transforming SolidBillets or Bars of Metal into Seamless Tubes, of which the following isa specification.

In another pending application for a patent I have described a method ofdeveloping a tubular formation from a solid metallic blank by theemployment of appropriately-adjusted diagonally-acting rolls or dies,the workingfaces of which are abruptly convergent. The product producedby the said method is not tubular throughout, but is solid at one end.This solid portion has to be cut off when the method is employed for themanufacture of tubes.

The present invention, by which I effect the transformation of a solidingot or blank intoa hollow body or tube which is open from end to end,consists in the combination, with the diagonally-acting rolls, of acomparatively slender rod, which is contained within the tube in theprocess of formation and made to abut against and hold back the solidcentral portion of the blank, and to thus effectually oppose thetendency of the solid central portion to move forward under theinfluence of the external diagonally-acting rolls, the result being thatthe ingot or blank is transformed into a tube whichis open from one endto the other. This method is especially useful for the manufacture ofseamless tubing from solid blanks composed of iron or steel, which require to be very highly heated preparatory to being subjected to theaction of the diagonal rolls.

As machines for diagonal rolling are well known, it is not deemednecessary to herein show or describe them, and the accompanying drawingstherefore simply illustrate various stages in the transformation ofaniron or steel blank into a seamless tube during its progress betweenthe convergent faces of two diagonally-acting conical rolls, midwaybetween which there is arranged a slender rod for at the proper timeabutting against and holding back the solid central portion of theblank.

The blank is so proportioned in diameter with reference to the angles ofconvergence and the width of the space between the working-faces of thediagonally-acting rolls that the tubular formation initiated by theaction of the rolls willhave a greater internal diameter than thediameter of the holding-back rod, and thus the end only of theholding-back rod will be in contact with the heated blank.

The drawings are as follows: Figure 1 affords a top view of a pair ofconical rolls, the axes of which occupy parallel vertical planes, butare inclined in opposite directions from a horizontal plane, alsoshowing a top view of the holding-back rod, which at one end is steppedor journaled in a standard or some stationary part of the machine andhas its free end projecting into the narrower part of the space betweenthe convergent workingfaces of the rolls. Figs. 2, 3, and 4. are viewssimilar to that shown in Fig. 1 of the diagonal rolls and of theholding-back rod.

In the figures the blank and the product resulting therefrom arerepresented in central longitudinal section, respectively, soon afterthe commencement at two intermediate stages and at the conclusion of theoperation of transforming the solid blank into a tube open from end toend.

For the sake of simplicity in description, it is assumed that the blankin all cases travels through a horizontal path between twodiagonally-acting rolls which are respectively arranged on either sideof it. The rolls A and B, which are slightly conical, so that theirworking faces are slightly convergent, rotate in the same direction, buttheir axes incline from the horizontal plane, respectively, in oppositedirections.

For operating on iron or steel it is desirable that the working-faces ofthe rolls shall have formed upon them spiral ribs, such as heretoforeused, or that they shall be otherwise so corrugated or roughened as toenable them to take a more effective hold upon the surface of the blank.

In Fig. 1 the solid blank 0 (shown in longitudinal section) isrepresented as having been seized and carried so far through the spacehe tween the rolls that the tubular formation has been initiated, butthe solid central portion of I00 the blank has not yet been carried farenough forward to be brought into collision with the blunt end d of theholding-back rod D. The

end d of the rod D is stepped in a stationary box, E, thus permittingthe rod D to rotate upon its longitudinal axis, but supporting it sothat by the abutment of its end 01 against the solid central portion ofthe blank 0. it is enabled to perform its function of holding back thesolid central portion of the blank.

Fig. 2 illustrates a further stage in the rolling operation, in whichthe tubular formation has been fully developed and the end 01 of theholding-back rod D is in contact with the solid central portion, 0, ofthe blank.

Fig. 3 represents a further advanced stage, at which, if desired, theholding-back rod may be removed, in which case the product will be atube open at one end and closed at the other.

Fig. 4 represents the conclusion of the operation, and shows theholding-back rod projecting entirely through the tube which has beenformed and having adhering to its end the small conical fragment 0*,which is sometimes punched out of the rear end of the blank 0.

In another pending application I have described the method of developinga tubular formation from a solid metallic blank solely by the action ofdiagonally acting rolls, in which case the necessary holding back of themain body of the blank is effected by the abruptly-convergingworking-faces of the rolls, and results from the extent to which thediameter of the blank is reduced while passing between the rolls.

The employment of the central holding-back rod as herein describedrendersit unnecessary to' reduce the diameter of the blank to so greatan extent as is required when the holding-back effect is obtained onlyby the bearing of the blank against the convergent faces of the rolls,and it follows, therefore, that when the holding-back bar is employedthe solid blank can be transformed into a tube with comparatively littlereduction in diameter. The bearing of the end of the holding-back rodagainst the center of the blank effects a compression of the metal atthat point, and thereafter the adjoining metal is pulled radiallyoutward from the center of the blank, and thereby the tubular formationis continued through to the rear end of the blank. The internal diameterof the resulting tubular product will be, to a greater or less extent,larger than the diameter of the holding-back rod, accordingly as thereduction in the diameter of the blank during its passage through therolls is greater or smaller.

The holding-back rod may be made of a single bar of metal, or it may beprovided with a detachable head ,which, if desired, may be of slightlylarger diameter than thediameter of the rod D. In Fig. l such a head, dis repre sented as socketed in the free end of the rod D.

What is claimed as the invention is 1. In the manufacture of seamlessmetal tubing, the improvement in the art of transforming solid metalblanks into tubes, which consists in holding back the solid centralportion of a suitably-heated blank by means of a holding-back rod whilethe blank is being subjected to the diagonal rolling and drawing actionof two or more rolls, the working-faces of which converge in aprescribed degree and the axes of which are relatively s0 arranged thata prescribed degree of obliquity is given to the direction in which theworking-faces of the rolls act, respectively, upon different sides ofthe blank, as and for the purposes set forth.

2. In the manufacture of seamless tubing from metal blanks by passingsuch blanks in a suitably-heated state between the workingfaces ofdiagonally-acting reducing-rolls, the herein-described means for holdingback the solid central portion of the heated blank, which consists of acentral] yplaced holding-back rod projecting into the space between therolls, and hence into the tube in process of formation,and abutting atits free end against the solid central portion of the blank, but nottouching the interior surface of the tube in process of for-. mation.

8. In diagonal rolling apparatus for imparting a tubular formation to asolid metallic blank, the combination, as herein set forth, of

two or more diagonally-acting rolls, theworking-faces of which areconvergent with a holding-back rod, the free end of which projects intothe space between the working-faces of the rolls in position to receiveat the proper time theimpact of the central portion of a solid blankwhich is being reduced in diameter and carried forward by theimpingement upon its surface of the diagonally-acting .rolls.

REINHARD MANNESMANN. lVitnesses:

FRITZ Konenr, GUSTAVE ALBERT OELRICI-IS.

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